The Tour Down Under has been cancelled for a second year because of the COVID-19 pandemic.
Australia's top cycling event was due to return in January next year, but event organisers have announced that international border closures and quarantine requirements made it too hard to stage.
Organisers made the call a month earlier than this time last year.
"We have fully explored all avenues, but unfortunately in the end it was the border closures and quarantine requirements for more than 400 people that make up the international teams that proved to still be too difficult to overcome," said Events SA executive director Hitaf Rasheed.
Adelaide's Festival Of Cycling, a domestic event covering a wide range of disciplines, will go ahead on January 21-29 in its place.
The Tour Down Under is the season-opening event for the men's WorldTour and the women's UCI ProTour.
It started in 1999 and has grown into a major SA tourism event.
Rasheed said its most recent edition in 2020 attracted 44,000 visitors, generated 742 jobs and brought more than $66 million into the state's economy.
The cancellation of the Adelaide Tour also casts doubts on Victoria's Cadel Evans Great Ocean Road race, which is held a few days later.
